This invention relates to a fluid driven blood pumping apparatus for use as an artificial heart. The apparatus of this invention is substantially flexible and fits well into the chest cavity of a patient for either temporary or permanent implantation.
Devices, such as U.S. Pat. Nos. 3,641,591 and 4,015,590, are known which use pneumatic or hydraulic pressures as a motive force to activate artificial hearts, or heart-assist devices for pumping blood.
The prior art devices, however, have been complex usually requiring two separate pressure sources, one for the artificial right ventricle and one for the artificial left ventricle with the corresponding duplication of the controls to provide the correct discharge pressures for each chamber and the coordination problems associated with working two separate pressure sources at different pressures.
Many of the artificial hearts which use atomic power or other elevated temperature power sources to drive them have a problem with dissipating the heat generated so that surrounding tissues may be heated which is not totally desirable.
Also, many of the prior art apparatus have had stress points within the internal working parts of the heart pump which caused stress failures in the parts and thus inhibited their use for fear of their failure.
As clotting of the blood in many of the artificial hearts has been a real danger and problem, the prior art has attempted many ways to prevent clotting. As stagnation in any part of the artificial heart can lead to potential clotting, the prior art has tried numerous ways to prevent stagnation of the blood, but these have been only partially successful.
Further, many of the prior art devices have fixed rigid walls which cause problems during the surgical procedure required to implant the device and thus required a greater trauma to the patient during surgical implantation. Also many of the fixed wall heart pumps have a fixed capacity volume which cannot be varied to allow for increased blood flow rates or decreased flow rates without necessarily increasing or decreasing the rate of the pumping or volume of the driving fluid used.
Many of the prior art devices have been very expensive and extremely complex.
Also in the fixed wall artificial heart no cardiac massage could be performed should a failure of the artificial heart occur.